Bag filling machine



Aug. 13, 1968 J. M. VAN PERNIS BAG FILLING MACHINE 2 Sheets-Sheet 1 Filed Dec. 17, 1.965

Aug. 13, J. VAN PERNIS 3,396,763

BAG FILLING MACHINE Filed Dec. 17, 1.965 2 Sheets-Sheet 2 United States Patent 3,396,763 BAG FILLING MACHINE John M. Van Pernis, Chicago, Ill., assignor to Black Products C0., a corporation of Illinois Continuation-impart of application Ser. No. 463,151,

June 11, 1965. This application Dec. 17, 1965, Ser.

10 Claims. (Cl. 141-68) ABSTRACT OF THE DISCLOSURE A device for filling bags with fluidized powdered material having a conditioning chamber with a valved outlet which terminates in a filling spout. The conditioning chamber is filled via an inlet tube extending about midway into the chamber and the inlet is formed with a collapsible pinch valve at its lower end. A pressurizing gas inlet is provided in the chamber above the lower end of the inlet and then gas is introduced via this inlet to dispense the powdered material, the pressure increase caused by this gas flow collapses the pinch valve and prevents further material flow into the chamber.

This invention relates to bag filling machines of the closed chamber type shown in my copending application Ser. No. 463,151, filed June 11, 1965, now Patent No. 3,322,219 granted May 30, 1967, of which this application is a continuation-in-part.

The characteristic of the machines of that application is the provision of an inlet pipe arrangement which avoids the use of the inlet valve and the level responsive device of certain prior art bag filling machines.

In the case of some materials I have discovered that when the gravitational head of the material in the supply hopper is reduced below a certain amount, that the material in the inlet pipe tends to be displaced in a manner which permits the air to blow out unless the pressure in the conditioning chamber is correspondingly reduced.

It is an object of my invention to provide an improved bag filling machine of the type described which is effective to prevent this blow out.

Other objects, features and advantages will become apparent as the description proceeds.

With reference now to the drawings in which like reference numerals designate like parts:

FIG. 1 is an elevation of a bag filling machine embodying my invention, a part of the conditioning chamber being broken away;

FIG. 2 is a section taken along line 22 of FIG. 1 showing the collapsible sleeve in section;

FIG. 3 is a side elevation of the conditioning chamber with a part broken away and showing the inlet pipe in its collapsed condition.

FIGS. 4 and 5 are fragmentary elevations of the collapsible sleeve, showing modifications; and

FIG. 6 is a diagram of the electrical control means.

FIG. 1 shows a bag filling machine 10 which is adapted for location beneath a supply hopper 11. The bag filling machine 10 includes a conditioning chamber 12 which communicates with the hopper 11 by means of an inlet pipe 13 having a collapsible end portion 32.

The bag filling machine 10 also includes a supporting framework 14, and a scale mechanism generally indicated by the reference numeral 15. A spout 16 communicates with the lower end of the conditioning chamber 12 by a flexible rubber tube 17, and suitable spout supporting mechanism 18 is provided which also provides a connection with the scale mechanism 15.

A difiuser pad 20 is located at the bottom of the con- 3,396,763 Patented Aug. 13, 1968 ditioning chamber 12 and is connected to an air supply pipe 21. A bag 19 may be supported from the spout 16.

When air is caused to flow through the supply line 21 and the diffuser pad 20, the material adjacent to the pad 20 within the conditioning chamber 12 is fluidized and will flow in a horizontal direction through the spout 16 into the bag 19. When the weight of the bag and contents reaches a predetermined amount such as pounds, the scale mechanism 15 is tripped and an air actuated pinch valve 22 engages the tube 17 to cut off the flow of material through the spout 16 in order to terminate the bag filling step. The fluidizing air to the pad 20 is also preferably cut oil at this time by a solenoid valve, not shown.

Communicating with the upper end of the conditioning chamber is a top air pipe 24, and a vent pipe 25. Interposed in each of these pipes are valves 26 and 27, respectively, which preferably are air actuated pinch valves, similar to the pinch valve 22.

The top air supply comprises a low pressure air pump 28, preferably a constant delivery pump having, for example, a rated delivery of from 60 down to 45 cubic feet per minute at pressure settings of from 3 to 6 pounds per square inch, respectively. However, the foregoing values are cited only to identify the type of pumpother sizes and ratings may be selected according to the particular situation. In general, air is supplied at a rate of .from 40 to 100 cubic feet per minute at from 2 to 6 pounds per square inch pressure. This constant delivery pump is sometimes referred to as a positive displacement blower.

The top air supply is also equipped with a relief valve 29 located between the pump 28 and the top air valve 26 so that the pressure can be regulated from between 2 to 6 pounds per square inch. Under this arrangement, and with a relatively large top air pipe 24, such as 2 inches I.D., the pressure within 'the free space 30 of the conditioning chamber will be brought up to the desired degree practically instantaneously, that is, within a small fraction of a second safer the top air valve 26 has been opened, and prior to the time that the material level 31 drops below the lower end of the inlet pipe 13. When the top air valve 26 is closed, air from the pump 28 bleeds out through the pressure relief valve 29. Thus it is possible to provide a large volume of air at a controlled pressure.

The lower end of the inlet pipe 13 terminates in a collapsible sleeve 32, such as a length of ordinary flexible nubber tubing, which is secured to the rigid portion 13a of the inlet tube 13 by a suitable clamping band 33. As soon as the pressure within the free space is greater than the pressure within the sleeve 32, the sleeve will tend to collapse. The pressure within the sleeve (disregarding atmospheric pressure) is determined primarily by the gravitational head of the material in the supply hopper. When complete collapse occurs, the collapsed sleeve acts as a valve which prevents blow out or other loss of pressure upwardly through the inlet pipe 13.

In the case of some powdered or fl-uffy materials such as cement and ground limestone, a partial collapse of the tube will compress the material so that the compressed material acts as an impervious plug which prevents air escape.

In other situations such as powdered resins, an upward movement of the material occurs which permits partial or total collapse of the tube prior to the time that blow out would otherwise occur.

In still other instances, the particles at the end of the inlet tube will drop away in spite of the pressure build up. This permits a flattening of the sleeve to take place which will reduce the cross section of the inlet tube and initiate a progressive collapse which will go through to completion.

Dropping away can also be caused by providing one or more perforations 34' (FIG. 4) in the collapsible sleeve a few inches above the lower edge. In the alternative, I provide two oppositely disposed vertical slits 35 in the lower end of the sleeve, as shown in FIG. 5. For example, as shown in FIG. 5, the slits are four inches long and one-quarter of an inch wide. The air passing into the inlet pipe 13 through the upper ends of the slits 35 will cause the particles adjacent the lower end of the sleeve 32 to drop away concurrently with the dropping away of the material level within the chamber, thus causing the flaps 36 to flatten out and move toward each other.

In the case of granular material and pellets, there may be an air leakage through the interstices of the granular material which delays the otherwise substantially instantaneous pressure build up. In such situations, the slits 35 accelerate the collapse.

As shown in FIGS. 1 and 2, two support rods 37 are preferably located within the sleeve 32, secured to and projecting downwardly from the rigid portion 13a of the inlet tube. These rods prevent inversion of the flexible sleeve under high chamber pressures, and also prevent distortion of the sleeve by the increase in material level. Thus the rods 37 cause the material level to be maintained with greater accuracy. Where the sleeve is slit, as in FIG. 5, the slits are aligned with the rods and the rods terminate right above the slits 35.

Suitable control means to be later described are provided for maintaining the top air valve 26 open and the vent valve 27 closed during the bag filling operation, and for reversing the conditions when the bag filling operation is terminated; that is, at the time of the trip when the scale mechanism opens the switch 41 (FIG. 6).

Thus, when the pressure within the chamber 12 is released, the gravitational head of the material exceeds the chamber pressure and causes the material to flow downwardly into the chamber until the level of the chamber material rises up to the FIG. 1 position wherein it blocks further downward movement. Then conditions remain in status quo until another bag filling operation is initiated.

The air supply for closing two of the air actuated pinch valves, the cut off valve 22 and the top air valve 26, is controlled by a normally open solenoid valve 46. The air supply for closing the air actuated vent valve 27 is controlled by the normally closed solenoid valve 23. The latter also controls the air supply 21 to the fiuidizing pad.

FIG. 6 shows a control circuit 40 which includes the solenoid valves 23 and 46, and a switch 41 which is actuated by the scale mechanism 15. When the switch 41 opens, the pinch valves 22 and 26 close, and the pinch valve 27 opens. The circuit 40 also includes a holding relay 42 which comprises a relay coil 43 and a switch 44 actuated thereby. The switch 44 also serves as a starting switch, being initially closed by a start button 45 to initiate the bag filling step.

In operation, the manual closing of the switch 44 opens the pinch valve 22 and turns on the air supply 21 so that the material adjacent to the fiuidizing pad will be fluidized and flow horizontally through the pinch valve 22 and into the bag 19. At the same time, the free space 30 serves as an air expansion chamber, permitting a portion of the fiuidizing air to flow upwardly through the material 38 in the conditioning chamber 12 to improve its fiuidizing characteristics.

The establishment of the control circuit 40 also opens the top air supply 24, and closes the vent so that almost instantaneously a low pressure of from 2 to 6 pounds is established within the free space and collapses the sleeve to shut off the flow of material through the inlet pipe 13 without loss of air pressure.

When the bag 19 is full, the scale mechanism 15 trips, breaking the circuit which closes the pinch valves 22 and 26, cutting off the flow through the spout 16 and terminating the bag filling step. At the same time, the top air supply 24 is cut off and also the fiuidizing air supply 21. The vent valve 27 is opened which causes the air pressure within the chamber 12 to drop to atmospheric pressure, which is less than the gravitational head pressure within the sleeve 32. Thus, the material within the supply hopper 11 flows downwardly through the inlet pipe 13 and pushes out the sleeve to its rounded FIG. 1 condition. Thereupon the conditioning chamber 12 is automatically filled up to the desired level, determined by the location of the lower end of the sleeve 32. Thus, the free space 30 is maintained and the apparatus is ready for the next bag filling step.

Although the collapsible portion 32 may be located above the lower end of the inlet pipe 13, that is, it may constitute an intermediate portion of the inlet pipe, the arrangement shown is preferred for space saving reasons.

The subject matter of my aforesaid copending application Ser. No. 463,151 is hereby incorporated by reference into this application, insofar as consistent with the present disclosure.

Although only preferred embodiments of my invention have been shown and described herein, it will be understood that various modifications and changes may be made in the construction shown without departing from the spirit of my invention as pointed out in the appended claims.

I claim:

1. In a bag filling machine of the automatic cut off type which includes a closed conditioning chamber, a bag filling spout communicating therewith, cut off means for arresting the flow of material from said conditioning chamber through said spout, the combination of a vertically disposed inlet pipe extending into said conditioning chamber and terminating at an intermediate point between the top and bottom thereof to provide a free space in the upper part of said conditioning chamber, said inlet pipe including a collapsible portion located within said conditioning chamber, means communicating with said chamber at a point above the lower end of said inlet pipe to supply air to said free space in substantial volume at a low pressure when said out off means is unoperated to at least partially collapse said collapsible portion, and vent means for said conditioning chamber operative when said out off means is operated to release the pressure on said collapsible portion.

2. A bag filling machine as claimed in claim 1 in which said collapsible portion is a length of rubber tubing, the remainder of said inlet pipe being rigid, and means for securing said rubber tubing to the lower end of said rigid portion.

3. A bag filling machine as claimed in claim 2 which includes two oppositely disposed vertically extending rods disposed within said rubber tubing adjacent to the inner surface thereof, and secured at their upper ends to said rigid portion.

4. A bag filling machine as claimed in claim 1 in which said collapsible portion constitutes the lower end of said inlet pipe.

5. A bag filling machine as claimed in claim 4 in which said collapsible portion is provided with a perforation located above the lower edge thereof.

6. A bag filling machine as claimed in claim 4 in which said collapsible portion is provided with two oppositely disposed slits extending upwardly from the lower edge thereof.

7. A bag filling machine as claimed in claim 6 in which said slits are substantially four inches long and one-quarter inch wide.

8. A bag filling machine of the automatic cut off type which includes a filling spout, a normally open cut off valve associated therewith, a closed conditioning chamber, and a normally closed vent for said chamber, comprising a vertically disposed inlet pipe extending into said conditioning chamber and terminating at about the half way point to provide a free space in the upper part of said conditioning chamber, air supply means including a constant delivery pump to supply air to said chamber in substantial volume at a predetermined pressure when said cut off valve is open, conduit means extending between said constant delivery pump and a point in said chamber located above the lower end of said inlet pipe, said inlet pipe including a collapsible sleeve portion located within said conditioning chamber and being deformable into at least a partially collapsed condition by the increase of pressure provided by said pump for cutting oft the fiow of material through said inlet pipe and for preventing the escape of air therethrough, and control means to shut off said air supply means and to open said vent when said out off valve is closed in order to release the pressure on said collapsible sleeve portion.

9. A bag filling machine comprising a closed conditioning chamber, a bag filling spout communicating with the lower end of said chamber for filling a bag suspended therefrom, a cut off valve located between said filling spout and said conditioning chamber, bag weight responsive means operative for closing said cut off valve when the Weight of the bag and contents exceeds a predetermined weight, a vertically disposed inlet pipe extending through the top wall of said chamber and terminating substantially below said top wall to provide a means for determining the initial level of material within said conditioning chamber, said inlet pipe including a collapsible sleeve portion located within said conditioning chamber for cutting off the flow of material through said inlet pipe, means for collapsing said sleeve comprising air supply means communicating with said chamber at a point above the lower end of said inlet pipe and including a normally open air supply valve, means controlled by said bag weight responsive means for closing said air supply valve when said cut off valve is closed, a vent pipe leading from the upper portion of said chamber, a normally closed vent valve for said vent pipe, and means controlled by said bag weight responsive means for opening said vent valve at the time that said cut off valve is closed, whereby the release of pressure on said sleeve portion will permit material to flow through said inlet pipe into said chamber, said air supply means supplying air to said free space in substantial volume at a low pressure.

10. A bag filling machine as claimed in claim 9 in which said air supply means includes a constant delivery pump and a pressure relief valve therefor.

References Cited UNITED STATES PATENTS 2,236,293 3/1941 Lund 137--525.1 X 2,659,442 11/1953 Sutlitf 137525.1 X 2,986,098 5/1961 Trout et al 137525.1 X 3,265,098 8/1966 ONeal et al 141-10 X 3,301,280 1/1967 Lau 141--68 3,324,906 6/1967 Chu 141-114 LAVERNE D. GEIGER, Primary Examiner.

E. J. EARLS, Assistant Examiner. 

